"SNL Presents: A Very Gilly Christmas" will air Dec. 17 at 8 PM. The two-hour special, the first for "SNL" since 2002, will be led by Wiig's Gilly, an ever-smiling Annie-lookalike who delights in violent mischief.

The special will feature new sketches with Gilly and highlights of classic holiday "SNL" sketches.

Wiig, roundly considered a standout performer on the NBC sketch comedy show, has built Gilly into a popular character. In a phone interview Monday, she said part of the fun of Gilly hosting is in her slim vocabulary, which consists mainly of the simple catch-phrase "Sorry."

"That can be a tough one to work around," Wiig said. "There's going to be no long monologue. Maybe her five-word vocabulary will stretch to 10 or 11."

A Gilly sketch is a very structured thing. It's always set in a classroom where an uncertain teacher (Will Forte) questions his students (Kenan Thompson, Bobby Moynihan) on the source of some trouble making.

Wiig and Paula Pell, a writer on the show, came up with the sketch while writing something else, but the idea continued to stick.

"We just kept doing the smile and we did it for a couple weeks," said Wiig. "We were just like, 'Let's write it.' Maybe she's this bad kid. We just started saying 'Sorry,' and it came organically from there."

Alec Baldwin and Steve Martin will also make guest appearances on the special to help introduce clips they've appeared in as hosts, including Baldwin in "NPR's Delicious Dish and the Schweddy Balls" and Martin in "A Holiday Wish."

If pressed for a holiday favorite, Wiig cites John Malkovich's maniacal reading of "'Twas the Night Before Christmas" last year.

"Since 'SNL' has been on for so long, it's 35 years of at least two or three shows a year kind of based on Christmas stuff," said Wiig. "There's a lot of good material there."